courier-encode 0.1.4

Python SDK for OpenAI-compatible inference endpoints (Courier and friends) with auto tool-call loops, structured outputs, and Whisper.

encode

One Python entry-point for any OpenAI-compatible LLM, with an auto-agent loop, durable sessions, and the brain/hands/session primitives from Anthropic's Managed Agents post baked in.

import encode

def get_weather(city: str) -> dict:
    """Get weather by city."""
    return {"city": city, "temp_f": 72}

out = encode.relay(
    model="gpt-4o-mini",
    messages=[{"role": "user", "content": "Weather in Denver?"}],
    tools=[get_weather],
).response

print(out.content)   # "It's 72°F in Denver."

That's the whole "hello world." The model called get_weather, encode dispatched it, fed the result back, and returned the final answer.

What encode is

A Python SDK for any OpenAI-compatible inference endpoint — Courier, OpenAI, vLLM, LM Studio, Ollama, Together, Groq, and more. One relay() function spans /v1/chat/completions and /v1/responses. Pass tools and it runs the loop to completion. Pass a Session and the run is durable. Pass a Terminal and your agent has a shell.

Why encode

• Auto tool loop. Drop a Python function in tools=; encode introspects the signature, builds the schema, runs the loop, and feeds results back. No decorators, no manual loop scaffolding.
• Both endpoints, one API. relay() auto-routes between /v1/chat/completions and /v1/responses — same handle, same tool loop, same intercept, same streaming consumer.
• Sessions as Pydantic event logs. Append-only, BYO storage. session.model_dump() to your DB; Session.model_validate() to resume — across processes, machines, or days.
• Mid-loop context engineering. Intercept callbacks can append, insert, replace, edit_last_tool_result, or compact the conversation that goes into the next iteration. Real context engineering in the harness, not just observation.
• ToolExecutor seam. Swap dispatch (local → remote → MCP → sub-agent) without touching the harness.
• Terminal as a first-class primitive. Persistent bash subprocess that retains cwd/env/venvs across calls. Wrap one in a closure and your agent has a shell.
• Full sync/async parity. Every helper has a *_async twin; async tool callables and async intercept callbacks just work.
• Streaming with the loop intact. Stream tokens and tool calls in real time across both endpoints.

60-second tour

import json
import encode

# 1. Plain chat
encode.relay(
    model="gpt-4o-mini",
    messages=[{"role": "user", "content": "hi"}],
).response.content

# 2. With a tool — auto-loop runs until the model stops calling tools
def lookup(q: str) -> dict:
    """Look something up."""
    return {"q": q, "answer": "42"}

encode.relay(
    model="gpt-4o-mini",
    messages=[{"role": "user", "content": "What's the meaning of life?"}],
    tools=[lookup],
).response.content

# 3. With a Session — durable, resumable, BYO persistence
session = encode.Session.open()
encode.relay(
    model="gpt-4o-mini",
    messages=[{"role": "user", "content": "remember: my name is Alex"}],
    session=session,
).response

# Persist anywhere — file, Postgres, Redis, S3...
open("/tmp/agent.json", "w").write(json.dumps(session.model_dump(), default=str))

# Resume anywhere
resumed = encode.Session.model_validate(json.loads(open("/tmp/agent.json").read()))
encode.relay(
    model="gpt-4o-mini",
    messages=[{"role": "user", "content": "what's my name?"}],
    session=resumed,
).response.content   # → "Alex"

Install

pip install encode

Python 3.10+. Configure with a .env (auto-loaded) or kwargs:

# .env
ENCODE_API_KEY=sk-your-key
ENCODE_BASE_URL=https://api.openai.com/v1

OPENAI_API_KEY / OPENAI_BASE_URL are also picked up if ENCODE_* aren't set.

What you can build

Multi-turn chat with stateful Messages — pass a Messages instance and it grows itself across relay() calls.

m = encode.Messages().system("Be brief.")
m.user("name three colors")
encode.relay(model="m", messages=m).response   # m now has the assistant turn too

An agent that stops when it submits a final answer.

def watcher(event):
    if any(tc.name == "submit_final" for tc in event.tool_calls):
        event.stop()

encode.relay(..., tools=[search, submit_final]).intercept(watcher).response

Mid-loop context compaction — trim, summarize, redact, or rewrite history without subclassing anything.

def trim(event):
    event.edit_last_tool_result(lambda c: c[:1000])

encode.relay(..., tools=[noisy_tool], on_intercept=trim).response

Auto tool discovery — the model calls a list_tools bootstrap, an intercept registers the discovered tools on the session, the next iteration uses them.

session = encode.Session.open(tools=[list_tools])

def discover(event):
    for tc in event.tool_calls:
        if tc.name == "list_tools":
            for spec in tc.result or []:
                event.register_tool(IMPLS[spec["function"]["name"]])

encode.relay(model="m", messages=[...], session=session,
             tools=session.tools, on_intercept=discover).response

A bash sandbox tool.

class BashSandbox:
    def __init__(self):
        self._term = None
    def as_tool(self):
        sandbox = self
        def bash(command: str) -> dict:
            """Run a bash command in a persistent shell."""
            self._term = self._term or encode.Terminal()
            r = self._term.run(command, timeout=10.0)
            return {"output": r.output, "exit_code": r.exit_code, "cwd": r.cwd}
        return bash

encode.relay(..., tools=[BashSandbox().as_tool()]).response

Docs

→ docs.md is the entry point — concept map + a link grid into focused topic pages:

quickstart · concepts · relay() · messages · tools · intercept · sessions · executors · terminal · streaming · structured output · whisper · async · errors · cookbook

Status & compatibility

• Python 3.10+
• macOS / Linux for Terminal (pexpect-backed)
• OpenAI-compatible endpoints: OpenAI, Courier, vLLM, LM Studio, Ollama, Together, Groq, and others

License

MIT